The present invention relates generally to the field of expandable vehicles, and more particularly to an operating mechanism for selectively extending and retracting a slide-out room of a motorized or towable vehicle.
In order to increase the available interior space of a motorized or towable vehicle such as a motor home or trailer, slide-out rooms can be made integral with the vehicle. When the vehicle is in transit, the slide-out room can be retracted and stored in the vehicle""s interior with the exterior wall of the slide-out room approximately flush with the vehicle""s exterior. As such, there is typically adequate space within the vehicle""s interior to accommodate users in transit and remain within the standard width limitations imposed upon a vehicle. When the vehicle is parked and leveled, the slide-out room is then slid outward through an opening formed in a sidewall of a fixed room, increasing the internal accommodations.
As shown in FIGS. 1A and 1B, a typical slide-out room 20 usually includes a floor section 22, a roof section 24, a first sidewall section 26, a second sidewall section 28, and a third sidewall section 30. In the retracted position, the roof section 24 and the first 26 and second sidewall section 28 are concealed from exterior view, and the third sidewall section 30 forms a portion of the vehicle""s sidewall. At the same time, the floor section 22 of the slide-out room 20 typically rests above a floor section 32 of a fixed room 34 and may form a portion of the usable interior floor during vehicle transit. Similarly, the roof section 24 of the slide-out room 20 may define the interior ceiling of that part of the vehicle during transit. The proximal ends of the roof section 24, first sidewall section 26, and second sidewall section 28, include stop walls 36. As used herein, xe2x80x9cproximalxe2x80x9d refers to the portion towards the vehicle body and xe2x80x9cdistalxe2x80x9d refers to the portion away from the vehicle body. The stop walls 36 form a L-shaped configuration with the respective roof section 24, first sidewall section 26, and second sidewall section 28. The stop walls 36 engage the inner surface 38 of a respective sidewall section 40 of the fixed room 34 when the slide-out room 20 is fully extended, and thereby limit the travel of the slide-out room
Weather sealing material 42, as in compressible strip form, is located on the abutting surfaces of the stop walls 36 and/or inner surface 38 of the respective sidewall 40 of the fixed room 34.
A number of slide-out extension mechanisms are currently used to extend and retract the slide-out room. Typically, a slide-out extension mechanism 44 includes a pair of support rails 46 which telescopically extend and retract from a pair of channels 48. The support rails 46 are attached to the slide-out room 20 and the channels 48 are attached to the fixed portion of the vehicle, such as the fixed room 34, wherein the slide-out room 20 retracts and extends with the retraction and extension of the support rails 46. The support rails 46 may be driven hydraulically, pneumatically, electrically or various combinations thereof. In the fully extended position, the support rails 46 extend outwardly in a cantilevered manner and support the slide-out room 20. The slide-out room 20 is further supported by the stop walls 36 abutting the inner surface 38 of the respective sidewall section 40 of the fixed room 34.
Since the slide-out room 20 is nested within a portion of the fixed room 34, it is usually dimensioned smaller than the fixed room 34. Thus, when the slide-out room 20 is in an extended position, the floor section 22 of the slide-out room 20 is higher than the floor section 32 of the fixed room 34. Such stepped flooring 50 has frequently been found to be undesirable, inconvenient, and somewhat hazardous. For example, a person may easily overlook the step and trip or stumble if care is not taken. Furthermore, the step limits the positioning of furniture within the room, and the step makes it difficult to create an aesthetically pleasing floor appearance.
In response, slide-out rooms 100 have been developed with flooring having a flush upper surface (see FIGS. 2A and 2B). Unfortunately, a slide-out mechanism 102 can be overly complicated, expensive, and relatively heavy. In the vehicular environment, unnecessary weight reduces fuel economy and may lead to an overly cumbersome vehicle. However, if the slide-out extension mechanism 102 is insufficiently rigid, flexing may lead to misalignment of the drive mechanism such that the support rails 104 are no longer extended/retracted in synchronism. As a result, the slide-out extension mechanism 102 may become skewed or bind during the transit sliding action. Another problem arising from an insufficiently rigid structure is that the slide-out room 100 may exhibit xe2x80x9cbouncingxe2x80x9d when a dynamic load is imposed on a floor section 106. This can be particularly annoying when an occupant causes the slide-out room 100 to bounce while walking. In severe cases, cantilevering forces acting on the slide-out mechanism 102 may cause the sidewall sections 108, 110, 112 of the slide-out room 100 to sag and the floor section 106 to separate at their abutting edges. Furthermore, slide-out rooms using multiple floor panels, either completely removable or foldable on hinges, may buckle, warp, split, and crack and permit air drafts to rise from the floor through the gaps created by the misaligned panels.
Referring to FIGS. 3A and 3B, another feature which is growing in popularity is the application of a flush wall system. In the flush wall system, proximal ends of a first sidewall section 150, second sidewall section 152 and roof section 154 of the slide-out room 156 are flush with an interior surface 158 of a respective sidewall section 160 of a fixed room 162 when the slide-out room 156 is fully extended. Weather sealing material 164 is placed along the edge of an opening 166 formed in the sidewall section 160 of the fixed room 162 to form a seal between the rooms 156, 162. By doing away with the stop walls 36, the interior aesthetics is greatly improved. However, the load which was once supported by the stop walls 36 is now redirected to a slide-out extension mechanism 168. As shown in FIG. 3A, cantilevered support rails 170 flex from the added load, and as a result, the slide-out room 156 extends outwardly at a downward incline relative to the fixed room 162. In addition to the awkward appearance of the floor section 172 of the slide-out room 156 being inclined relative to a floor section 174 of the fixed room 162, the proximal end of the floor section 172 of the slide-out room 156 protrudes upwardly and a gap g is formed in the flooring. Furthermore, the seal between the rooms 156, 162 is ineffective because a gap is formed between the rooms 156, 162 due to the misalignment of the sidewall sections 150, 152 and roof section 154 of the slide-out room 156. Since vehicles of this type are often used during inclement weather, water, snow, and cold/hot air drafts may leak into the interior of the vehicle and create an inhospitable environment. In addition, certain vehicles such as medical and dental trailers require sterile environments.
In order to further increase the available interior space of vehicles, there is a growing trend to provide increasingly larger slide-out rooms. To accommodate larger sized slide-out rooms, the cantilevered support rails are lengthened. As a result of lengthening the cantilevered support rails and the increased weight of the slide-out room, the slide-out extension mechanism is more prone to flexing. In addition to the weight of the larger sized slide-out room, existing slide-out mechanism must support the additional weight resulting from furnishing the vehicle with amenities more commonly found in houses such as a microwave oven, refrigerator, dishwasher, washer/dryer, entertainment centers, desktop computer and related accessories. Furthermore, the slide-out extension mechanism must support larger sized furniture such a full size dining table, book shelves, cabinets and the like.
Thus, there remains a need for an improved slide-out extension mechanism which is capable of extending and retracting a slide-out room in a reliable, easily operated, and quiet manner that can be either incorporated into a vehicle body during manufacturing or retrofitted onto existing vehicle bodies. Furthermore, there remains a need to provide a slide-out extension mechanism which is relatively inexpensive and lightweight and yet sufficiently rigid.
In accordance with the present invention, a vehicle is provided with a slide-out extension mechanism capable of extending and retracting a slide-out room in a reliable, easily operated, and quiet manner that can be either incorporated into a vehicle body during manufacturing or retrofitted onto existing vehicle bodies. Furthermore, the slide-out extension mechanism is relatively inexpensive and lightweight and yet sufficiently rigid to support large sized slide-out rooms having flush flooring and flush sidewalls.
In an exemplary embodiment, the vehicle includes a fixed room and a slide-out room which extends and retracts relative to the fixed room. The fixed room includes a floor section, sidewall sections, and a roof section, and the slide-out room includes a floor section, sidewall sections, and a roof section. A slide-out extension mechanism extends and retracts the slide-out room in a cantilevered manner. In a fully retracted position, the roof section and two of the sidewall sections of the slide-out room are typically concealed from exterior view and a third sidewall section of the slide-out room forms a portion of the sidewall section of the fixed portion of the vehicle. Furthermore, the floor section of the slide-out room is flush with the floor section of the fixed room, and proximal ends of the sidewall sections of the slide-out room are flush with an inner surface of one of the sidewall sections of the fixed room. The slide-out extension mechanism includes a channel which is secured to the fixed room and a support rail is slidingly coupled to the channel. The support rail is secured to the slide-out room such that extension and retraction of the support rail causes the slide-out room to similarly extend and retract.
One of the problems encountered with large sized slide-out rooms with flush floor sections and sidewall sections is that large loads may cause undesired flexing of the slide-out extension mechanism. Excessive complexity, expense, and weight is reduced by preferentially increasing the rigidity of the slide-out mechanism where needed. It has been determined that existing slide-out extension mechanisms are usually sufficiently rigid in the x-y direction but require additional rigidity in the z direction. For support rails having a rectangular-shaped cross section, bending rigidity in the z direction is primarily dependent upon the thickness of the vertically oriented walls, while bending rigidity in the z-y directions is primarily dependent upon the thickness of the horizontally oriented walls. In the present invention, the combined thickness of the vertically oriented walls is increased by providing support rails including a first tube attached to a second tube, wherein the thickness of the horizontally oriented walls is not increased. With the twin tube configuration, standardized tubes having a uniform wall thickness may be utilized instead of a single tube configuration which requires a costly, custom fabricated tube with differing horizontal and vertical wall thicknesses. The combined thickness of the vertically oriented walls is further increased by providing a gear rack with a wall portion disposed between the first tube and the second tube.
In another embodiment of the present invention, a vehicle is provided with a slide-out room having a storage compartment. A distal portion of the support rail is provided with a pivot member, and a longitudinal axis of the pivot remains in a substantially horizontal position during the extension and retraction of the slide-out room. The storage compartment is attached to the pivot member and extends and retracts in unison with the extension and retraction of the slide-out room. Furthermore, the storage compartment remains in a substantial horizontal position during the extension and retraction process.